Waste water treatment systems are taking on increasing importance as time passes. More waste water than ever is being generated, and the harmful effects of dumping untreated waste water into the environment are becoming more evident.
One specific need for suitable waste water treatment systems is in the area of industrial high pressure washing (e.g., for use in cleaning industrial equipment, engines, boats, etc.). The resulting waste water contains a variety of contaminants, including a substantial amount of oil and other debris. Such waste water is highly amenable to recycling and reuse in the same pressure washing system.
The need to separate oil from water as a preliminary matter in waste water treatment processes has long been recognized. Traditional oil separators have utilized a variety of ways to separate oil from water, such as tanks with a series of baffles and deflector plates, chemicals, and gas injection systems. Typically, separation of oil occurs prior to further clarification and filtration of the waste water.
Oil and water have different densities compared to one another and therefore tend to separate one from another after they have been mixed together. Oil has a lower relative density compared to water. and therefore will separate and rise above water in a vessel. The rate at which separation occurs depends, in large measure, upon the size of oil droplets mixed with the water. The bigger the droplet of oil, the more rapidly it will separate from water. Therefore, anything that will cause oil to coalesce will speed up separation.
One type of a prior oil separator is shown in U.S. Pat. No. 4,014,791. This patent discloses an oil separator unit having a deflector plate at the terminating end of the inlet pipe to reverse the flow of incoming fluid. This causes the fluid to interact with itself to stimulate separation of oil from the water. Another example is U.S. Pat. No. 4,064,054, which involves a wash tank having a plurality of baffle sections for promoting separation of oil from the water.
There remains a need, however, to provide an efficient, effective oil separator apparatus for use in waste water treatment systems. Specifically, there is a need to provide an oil separator that increases the rate by which oil coalesces, thereby accelerating the rate at which oil separates from waste water.
The present invention involves a first stage oil separator apparatus which promotes rapid coalescing of oil as it enters into a separator tank. The invention further involves a second stage separator apparatus wherein waste water from the first stage oil separator is directed through a polypropylene bead pack for further separation of residual oil and debris from the waste water. The waste water treatment system of the present invention is a flow-through system. Other features, advantages, and objects of the invention will become apparent from the detailed disclosure that follows.